Modified metalloaluminophosphate molecular sieves

ABSTRACT

The invention is directed to a method for modifying a microporous metalloaluminophosphate molecular sieve, the method comprising the steps of a) introducing a metal hydride compound within the cages of said microporous molecular sieve, and b) reacting said metal hydride compound with the acid groups located in the cages of the molecular sieve, wherein the metal hydride compound is selected from the group consisting of hydrides of metals of Groups 1 and 2 of the Periodic Table, compounds of formula M 1 M 2 H 4  and mixtures thereof, M 1  being a metal belonging to Group 13 of the Periodic Table and M 2  being a metal belonging to Group 1 of the Periodic Table. The invention also relates to modified metalloaluminophosphate molecular sieves, to catalyst particles containing them and the use of the modified metalloaluminophosphate molecular sieves in catalytic processes.

FIELD OF INVENTION

[0001] The present invention relates to modified metalloaluminophosphatemolecular sieves, preferably modified silicoaluminophosphate molecularsieves, as well as to methods of preparing these modified molecularsieves. The present invention also relates to the use of these modifiedmolecular sieves in catalytic processes, such as processes for theconversion of oxygenated hydrocarbon feedstocks.

BACKGROUND OF THE INVENTION

[0002] Olefins, particularly light olefins, have been traditionallyproduced from petroleum feedstocks by either catalytic or steamcracking. Oxygenates, however, are becoming an alternative feedstock formaking light olefins, particularly ethylene and propylene. Promisingoxygenate feedstocks are alcohols, such as methanol and ethanol,dimethyl ether, methyl ethyl ether, diethyl ether, dimethyl carbonate,and methyl formate. Many of these oxygenates can be produced from avariety of sources including natural gas. Because of the relativelylow-cost of these sources, alcohol, alcohol derivatives, and otheroxygenates have promise as an economical source for light olefinproduction.

[0003] One way of producing olefins is by the conversion of methanol toolefins (MTO) catalyzed by a molecular sieve. Useful molecular sievesfor converting methanol to olefin(s) are non-zeolitic molecular sieves,in particular metalloaluminophosphates such as thesilicoaluminophosphates (SAPO's). For example, U.S. Pat. No. 4,499,327to Kaiser, fully incorporated herein by reference, discloses makingolefins from methanol using a variety of SAPO molecular sieve catalysts.The process can be carried out at a temperature between 300° C. and 500°C., a pressure between 0.1 atmosphere to 100 atmospheres, and a weighthourly space velocity (WHSV) of between 0.1 and 40 hr⁻¹. Crystallinealuminosilicate zeolites have also been reported as catalysts forconverting methanol and/or dimethyl ether to olefin-containinghydrocarbon mixtures. For example, U.S. Pat. No. 3,911,041 disclosesthat methanol can be converted to C2-C4 olefins by contacting themethanol at a temperature of 300° C. to 700° C. with a crystallinealuminosilicate zeolite catalyst which has a Constraint Index of 1-12,such as ZSM-5, and which contains at least 0.78% by weight of phosphorusincorporated in the crystal structure of the zeolite.

[0004] Zeolitic aluminosilicate molecular sieves contain athree-dimensional microporous crystal framework structure of [SiO₂] and[AlO₂] corner sharing tetrahedral units. Metalloaluminophosphate (MeAPO)molecular sieves, often qualified as non-zeolitic molecular sieves,contain a three-dimensional microporous crystal framework structure of[MO₂], [AlO₂] and [PO₂] corner sharing tetrahedral units. When M issilicon, the molecular sieves are referred to as silicoaluminophosphate(SAPO) molecular sieves. There are a wide variety of aluminosilicate andMeAPO molecular sieves known in the art. Of these the more importantexamples as catalysts for the conversion of oxygenates to olefinsinclude ZSM-5, ZK-5, ZSM-11, ZSM-12, ZSM-34, ZSM-35, erionite,chabazite, offretite, silicalite and other similar materials, SAPO-5,SAPO-11, SAPO-17, SAPO-18, SAPO-34, SAPO-35, SAPO-41, SAPO-56 and othersimilar materials. SAPO molecular sieves having the CHA framework typeand especially SAPO-34 are particularly important catalysts. Anotherimportant class of SAPO molecular sieves consists of mixed or intergrownphases of molecular sieves having the CHA and AEI framework types.Examples of such materials are disclosed in WO 98/15496, published 16Apr. 1998, and in WO 02/070407, published Sep. 12, 2002, both hereinfully incorporated by reference.

[0005] While the aforementioned molecular sieves exhibit good catalyticproperties in the conversion of methanol to olefins, there remains aneed to improve their catalytic performance in order to decrease theirselectivity to undesired saturated hydrocarbons and to increase theirselectivity to desired light olefins (ethylene and propylene).

[0006] Various methods have been reported for treating and/or modifyingcrystalline molecular sieves in order to improve their catalyticperformances. U.S. Pat. No. 5,250,484 discloses a method for making asurface inactivated catalyst composition comprising acidic porouscrystalline material, in particular ZSM-23, having active internalBroensted acid sites and containing surface inactivating material havingboron to nitrogen bonds. The method involves contacting the surface ofthe molecular sieve with aqueous ammonia borane solution. The modifiedcatalysts are described for use in olefin oligomerization processes.

[0007] U.S. Pat. No. 6,046,371 discloses silylatedsilicoaluminophosphate compositions prepared by contacting calcinedSAPOs with a silylating agent, preferably tetraalkyl orthosilicates andpoly(alkylaryl)siloxanes. The silylated silicoaluminophosphatecompositions are described as giving increased light olefin yields anddecreased coke production, when used as catalysts in the conversion ofoxygenated hydrocarbons to olefins.

[0008] U.S. Pat. No. 6,472,569 discloses catalyst systems comprising asilicoaluminophosphate impregnated with a compound selected from thegroup consisting of phosphoric acid, boric acid, tributyltin acetate,and combinations of any two or more thereof. These catalyst systems aredescribed as giving increased light olefin yields and decreased cokeproduction, when used as catalysts in the conversion of oxygenatedhydrocarbons and/or ethers.

[0009] PCT Application WO 02/085514-A2 discloses a process for modifyinga microporous framework defined by nanocages, such as SAPO-18 orSAPO-34. The modified microporous framework comprises and an inorganiccompound in at least one of the nanocages, wherein said inorganiccompound is a product formed by a reaction of a second inorganicmolecule that has a kinetic diameter smaller than the kinetic diameterof the inorganic compound. The second inorganic compound is selectedfrom the group consisting of PH₃, SiH₄, Si₂H₆ and B₂H₆. The inorganiccompound may be selected from the group consisting of phosphoric acid,boric acid, silica, a product of the hydrolysis of PH₃, a product of thehydrolysis of SiH₄, a product of the hydrolysis of Si₂H₆, a product ofthe hydrolysis of B₂H₆, a product of the oxidation of PH₃, a product ofthe oxidation of SiH₄, a product of the oxidation of Si₂H₆ and a productof the oxidation of B₂H₆. This document discloses more specifically aprocess for modifying H-SAPO-34 by treating H-SAPO-34 with PH₃ andmethanol in a reactor at 250° C., followed by heating to 600° C. Themethod requires the presence of methanol to form P(CH₃)₃ and P(CH₃)₄ ⁺species in the SAPO-34 nanocages. According to this document, themodified H-SAPO-34 delivers higher ethylene selectivity than unmodifiedH-SAPO-34.

[0010] Despite the various molecular sieve modifications reported in theliterature, there remains a need to find other methods for improvingmolecular sieve catalytic performances, in order to decrease theselectivity of these molecular sieves to undesired saturatedhydrocarbons and to increase their selectivity to desired light olefins(ethylene and propylene), when used as catalysts in the conversion ofoxygenated hydrocarbons.

SUMMARY OF THE INVENTION

[0011] The present invention provides a method for modifying amicroporous metalloaluminophosphate molecular sieve, the methodcomprising the steps of a) introducing a metal hydride compound withinthe cages of said microporous molecular sieve, and b) reacting saidmetal hydride compound with the acid groups located in the cages of themolecular sieve, wherein the metal hydride compound is selected from thegroup consisting of hydrides of metals of Groups 1 and 2 of the PeriodicTable, compounds of formula M¹M²H₄ and mixtures thereof, M¹ being ametal belonging to Group 13 of the Periodic Table and M² being a metalbelonging to Group 1 of the Periodic Table. Preferably, M¹ is aluminum,boron, or a mixture of aluminum and boron.

[0012] In a preferred embodiment, reacting the metal hydride with themolecular sieve acid groups takes place at a temperature of from roomtemperature to 150° C.

[0013] In another preferred embodiment, molecular sieve with a solutionor a slurry of the metal hydride compound in an aprotic organic solvent,more preferably under conditions that avoid the presence of water and/oralcohols.

[0014] The preferred molecular sieves that are modified according tothis method are small pore or medium metalloaluminophosphate molecularsieves, more preferably SAPO-34 or SAPO-56.

[0015] In yet another embodiment, the method for modifying the molecularsieve further comprises a step of c) restoring at least a portion of theacid groups located in the cages of the molecular sieve by submittingthe molecular sieve to a thermal treatment, preferably at a temperatureof from about 30° C. to about 400° C., more preferably at a temperatureof from 50° C. to 150° C. In a separate preferred embodiment, thermaltreatment takes place in the presence of water, an alcohol, such asmethanol, ethanol or mixtures thereof, nitrous oxides, carbon monoxide,carbon dioxide, sources of ammonia, and mixtures thereof.

[0016] The invention also relates to a microcrystallinemetalloaluminophosphate molecular sieve having acid sites within itsintracrystalline cages bound with a metal compound, the metal compoundbeing selected from the group consisting of hydrides of metals of Groups1 and 2 of the Periodic Table, compounds of formula M¹M²H₄ and mixturesthereof, M¹ being a metal belonging to Group 13 of the Periodic Tableand M² being a metal belonging to Group 1 of the Periodic Table.Preferably, M¹ is aluminum, boron, or a mixture of aluminum and boron.

[0017] The present invention further relates to a method of makingmolecular sieve catalyst particles, the method comprising a) combining amicrocrystalline metalloaluminophosphate molecular sieve having acidsites within its intracrystalline cages bound with a metal compound, themetal compound being selected from the group consisting of M¹H_(x),M¹M²H_(y), M² and M³-H wherein M¹ is a metal belonging to Group 13 ofthe Periodic Table; M² is a metal belonging to Group 1 of the PeriodicTable; and M³ is a metal belonging to Group 2 of the Periodic Table, xranging from 1 to 2 and y ranging from 1 to 3, with at least one binderand optionally at least one matrix to form a catalyst preparationmixture; b) forming catalyst particles from the catalyst preparationmixture obtained at step a); c) submitting the catalyst particles to athermal treatment at a temperature of from about 30° C. to about 700° C.Preferably, the thermal treatment step is carried out in the presence ofwater, an alcohol, such as methanol, ethanol or mixtures thereof,nitrous oxides, carbon monoxide, carbon dioxide, sources of ammonia, andmixtures thereof.

[0018] In yet another embodiment, the present invention relates to aprocess for making olefins from an oxygenate feedstock comprising thesteps of a) providing a metalloaluminophosphate molecular sieve; b)introducing a metal hydride compound within the cages of saidmicroporous molecular sieve; c) reacting said metal hydride compoundwith the acid groups located in the cages of the molecular sieve,wherein the metal hydride compound is selected from the group consistingof hydrides of metals of Groups 1 and 2 of the Periodic Table, compoundsof formula M¹M²H₄ and mixtures thereof, M¹ being a metal belonging toGroup 13 of the Periodic Table and M² being a metal belonging to Group 1of the Periodic Table. Preferably, M¹ is aluminum, boron, or a mixtureof aluminum and boron; d) restoring at least a portion of the acidgroups located in the cages of the molecular sieve by submitting themolecular sieve to a thermal treatment; e) contacting the molecularsieve obtained at step d) with the oxygenate feedstock; f) recovering anolefin product.

DETAILED DESCRIPTION OF THE INVENTION

[0019] Introduction.

[0020] Molecular sieve materials such as metalloaluminophosphatemolecular sieves (MeAPOs) comprise a three-dimensional microporouscrystal framework structure. After calcination, they possess a voidvolume consisting of channels and cages within their molecularframework. Recent studies by Kolboe et al. and by Haw et al. indicatethat the catalytic conversion of methanol to olefins over SAPO-34proceeds through a so-called “hydrocarbon pool” mechanism (Dahl,physical characteristics. Molecular sieves have been well classified bythe Structure Commission of the International Zeolite Associationaccording to the rules of the IUPAC Commission on Zeolite Nomenclature.A framework-type describes the topology and connectivity of thetetrahedrally coordinated atoms constituting the framework, and makes anabstraction of the specific properties for those materials.Framework-type molecular sieves for which a structure has beenestablished, are assigned a three letter code and are described in theAtlas of Zeolite Framework Types, 5th edition, Elsevier, London, England(2001), which is herein fully incorporated by reference.

[0021] Crystalline molecular sieve materials all have 3-dimensional,four-connected framework structure of corner-sharing TO₄ tetrahedra,where T is any tetrahedrally coordinated cation. These molecular sievesare typically described in terms of the size of the ring that defines apore, where the size is based on the number of T atoms in the ring.Other framework-type characteristics include the arrangement of ringsthat form a cage, and when present, the dimension of channels, and thespaces between the cages. See van Bekkum, et al., Introduction toZeolite Science and Practice, Second Completely Revised and ExpandedEdition, Volume 137, pages 1-67, Elsevier Science, B.V., Amsterdam,Netherlands (2001). In a preferred embodiment, the molecular sieve is ametalloaluminophosphate molecular sieve, more preferably asilicoaluminophosphate molecular sieve, having 8- or 10-ring structures,most preferably having 8-rings and an average channel pore size lessthan about 5 Å, preferably in the range of from 3 Å to about 5 Å, morepreferably from 3 Å to about 4.5 Å, and most preferably from 3.5 Å toabout 4.2 Å.

[0022] Non-limiting examples of small pore molecular sieves aremolecular sieves that have the framework types AEI, AFT, AFX APC, ATN,ATT, ATV, AWW, BIK, CAS, CHA, CHI, DAC, DDR, EDI, ERI, GOO, KFI, LEV,LOV, LTA, MON, PAU, PHI, RHO, ROG, THO. Non-limiting examples of mediumpore molecular sieves are molecular sieves that have the framework typesAFO, AEL, EUO, HEU, FER, MEL, MFI, MTW, MTT, TON. Non-limiting examplesI. M., Kolboe, S., Catal. Lett., 1993, 20, 329-336; Dahl, I. M., Kolboe,S., J. Catal., 1994, 149, 458-464; Dahl, I. M., Kolboe, S., J. Catal.,1996, 161, 304-309; Goguen, P. W., Xu, T., Barich, D. H., Skloss, T. W.,Song, W., Wang, Z., Nicholas, J. B., Haw, J. F., J. Am. Chem. Soc.,1998, 120, 2650-2651; Song, W., Haw, J. F., Nicholas, J. B., Heneghan,C. S., J. Am. Chem. Soc., 2000, 122, 10726-10727; Song, W., Haw, J. F.,J. Am. Chem. Soc., 2001, 123, 4749-4754; Song, W., Fu, H., Haw, J. F.,J. Phys. Chem. B, 2001, 105, 12839-12843; Arstad, B., Kolboe, S., Catal.Lett., 2001, 71, 209-212; Arstad, B., Kolboe, S., J. Am. Chem. Soc.,2001, 123, 8137-8138; PCT Application WO 02/085514). According to thismechanism, and without wishing to be bound to any theory, methylatedaromatic compounds (methylated benzene and/or methylated naphthalene)form within the molecular sieve cages during the methanol to olefinsconversion. The amount and type of methylated aromatic compounds presentin the molecular sieve cages are dependent on the number of acid sitesin the molecular sieve cages, as well as on the size and shape of themolecular sieve cages. The amount and type of aromatic compounds presentin the cages is believed to influence product selectivity during theconversion of methanol to light olefins.

[0023] The present invention is directed toward a method of partiallyfilling the void volume of a microporous molecular sieve with a VolumeModifier, while maintaining the acid sites within the channels and cagesof the molecular sieve. After this modification, the molecular sievepossesses increased selectivity to desired products, such as ethyleneand propylene, and lowered selectivity to undesired products, such aspropane and saturated and unsaturated hydrocarbons having more than 3carbon atoms, when used to catalyze the conversion of oxygenates. Thepresent invention provides an important catalytic improvement, not onlyfor molecular sieves already known for their good performances in theoxygenates-to-olefins conversion such as SAPO-34, but also for othermolecular sieves.

[0024] The modified molecular sieves of the present invention areobtained by modifying crystalline molecular sieves that can have a widerange of chemical and of large pore molecular sieves are molecularsieves that have the framework types BEA, CFI, EMT, FAU, LTL, MWW. Othernon-limiting examples of molecular sieves include ANA, CLO, DON, GIS,MER, MOR, and SOD. Non-limiting examples of the preferred molecularsieves, particularly for converting an oxygenate containing feedstockinto olefin(s), include AEI, AFX, BEA, CHA and KFI. In a more preferredembodiment, the molecular sieve of the invention has a CHA, KFI or AFXtopology, or a combination thereof, most preferably an AFX topology.

[0025] Non limiting examples of preferred molecular sieves of theinvention include one or a combination of SAPO-5, SAPO-8, SAPO-11,SAPO-16, SAPO-17, SAPO-18, SAPO-20, SAPO-31, SAPO-34, SAPO-35, SAPO-36,SAPO-37, SAPO-40, SAPO-41, SAPO-42, SAPO-44, SAPO-47, SAPO-56, AlPO-5,AlPO-11, AlPO-18, AlPO-31, AlPO-34, AlPO-36, AlPO-37, AlPO-46, and metalcontaining molecular sieves thereof. The more preferred molecular sievesof the invention include one or a combination of SAPO-17, SAPO-34,SAPO-35, SAPO-44, SAPO-56, AlPO-18 and AlPO-34, even more preferably oneor a combination of SAPO-34 and SAPO-56, and metal containing molecularsieves thereof.

[0026] Crystalline Molecular Sieve Synthesis

[0027] The crystalline molecular sieves that can be modified accordingto the present invention may be prepared by a wide range of methods,well known in the art. Generally, molecular sieves are synthesized bythe hydrothermal crystallization of one or several of a source ofaluminum, a source of phosphorous, a templating agent, and a source ofmetal, preferably silicon. Typically, a combination of the selectedsources of aluminum and phosphorous, optionally with one or moretemplating agents and/or one or more sources of silicon and/or othermetal, are placed in a sealed pressure vessel, optionally lined with aninert plastic such as polytetrafluoroethylene, and heated, at acrystallization pressure and crystallization temperature, until acrystalline material is formed, and then recovered by filtration,centrifugation and/or decanting. In a preferred embodiment, at least onetemplating agent and at least one source of metal, most preferablysilicon, is used.

[0028] Non-limiting examples of silicon sources include silicates, fumedsilica, for example, Aerosil-200 available from Degussa Inc., New York,N.Y., and CAB-O-SIL M-5, silicon compounds such as tetraalkylorthosilicates, for example, tetramethyl orthosilicate (TMOS) andtetraethylorthosilicate (TEOS), colloidal silicas or aqueous suspensionsthereof, for example Ludox-HS-40 sol available from E.I. du Pont deNemours, Wilmington, Del., silicic acid, alkali-metal silicate, or anycombination thereof. The preferred source of silicon is a silica sol.

[0029] Non-limiting examples of aluminum sources includealuminum-containing compositions such as aluminum alkoxides, for examplealuminum isopropoxide, aluminum phosphate, aluminum hydroxide, sodiumaluminate, pseudo-boehmite, gibbsite and aluminum trichloride, or anycombinations thereof. A preferred source of aluminum is pseudo-boehmite,particularly when producing a silicoaluminophosphate molecular sieve.

[0030] Non-limiting examples of phosphorous sources, which may alsoinclude aluminum-containing phosphorous compositions, includephosphorous-containing, inorganic or organic, compositions such asphosphoric acid, organic phosphates such as triethyl phosphate, andcrystalline or amorphous aluminophosphates such as AlPO₄, phosphoroussalts, or combinations thereof. The preferred source of phosphorous isphosphoric acid, particularly when producing a silicoaluminophosphate.

[0031] Templating agents are generally compounds that contain elementsof Group 15 of the Periodic Table of Elements, particularly nitrogen,phosphorus, arsenic and antimony, more preferably nitrogen orphosphorous, and most preferably nitrogen. Typical templating agents ofGroup 15 of the Periodic Table of elements also contain at least onealkyl or aryl group, preferably an alkyl or aryl group having from 1 to10 carbon atoms, and more preferably from 1 to 8 carbon atoms. Thepreferred templating agents are nitrogen-containing compounds such asamines and quaternary ammonium compounds.

[0032] The quaternary ammonium compounds, in one embodiment, arerepresented by the general formula R₄N⁺, where each R is hydrogen or ahydrocarbyl or substituted hydrocarbyl group, preferably an alkyl groupor an aryl group having from 1 to 10 carbon atoms. In one embodiment,the templating agents include a combination of one or more quaternaryammonium compound(s) and one or more of a mono-, di- or tri- substitutedamine.

[0033] Non-limiting examples of templating agents include tetraalkylammonium compounds including salts thereof such as tetramethyl ammoniumcompounds including salts thereof, tetraethyl ammonium compoundsincluding salts thereof, tetrapropyl ammonium compounds including saltsthereof, and tetrabutylammonium compounds including salts thereof,cyclohexylamine, morpholine, di-n-propylamine (DPA), tripropylamine,triethylamine (TEA), triethanolamine, piperidine, 2-methylpyridine,N,N-dimethylbenzylamine, N,N-diethylethanolamine, dicyclohexylamine,N,N-dimethylethanolamine, choline, N,N′-dimethylpiperazine,1,4-diazabicyclo(2,2,2)octane, N′,N′,N,N-tetramethyl-(1,6)hexanediamine,N-methyldiethanolamine, N-methyl-ethanolamine, N-methyl piperidine,3-methyl-piperidine, N-methylcyclohexylamine, 3-methylpyridine,4-methyl-pyridine, quinuclidine, N,N′-dimethyl-1,4-diazabicyclo(2,2,2)octane ion; di-n-butylamine, neopentylamine, di-n-pentylamine,isopropylamine, t-butylamine, ethylenediamine, pyrrolidine, and2-imidazolidone.

[0034] Generally, the synthesis mixture described above is sealed in avessel and heated, preferably under autogenous pressure, to atemperature in the range of from about 80° C. to about 250° C.,preferably from about 100° C. to about 250° C., more preferably fromabout 125° C. to about 225° C., even more preferably from about 150° C.to about 180° C.

[0035] In yet another embodiment, the crystallization temperature isincreased gradually or stepwise during synthesis, preferably thecrystallization temperature is maintained constant, for a period of timeeffective to form a crystalline product. The time required to form thecrystalline product is typically from immediately up to several weeks,the duration of which is usually dependent on the temperature; thehigher the temperature the shorter the duration. In one embodiment, thecrystalline product is formed under heating from about 30 minutes toaround 2 weeks, preferably from about 45 minutes to about 240 hours, andmore preferably from about 1 hour to about 120 hours.

[0036] In one embodiment, the synthesis of a molecular sieve is aided byseeds from another or the same framework type molecular sieve.

[0037] The hydrothermal crystallization is carried out with or withoutagitation, for example stirring or tumbling. The stirring or agitationduring the crystallization period may be continuous or intermittent,preferably continuous agitation. Typically, the crystalline molecularsieve product is formed, usually in a slurry state, and is recovered byany standard technique well known in the art, for example centrifugationor filtration. The isolated or separated crystalline product, in anembodiment, is washed, typically, using a liquid such as water, from oneto many times. The washed crystalline product is then optionally dried,preferably in air.

[0038] Depending on the ratio and the type of ingredients used toprepare the molecular sieve, molecular sieves with high or low silicon(Si) to aluminum (Al) ratios can be obtained. The pH of a reactionmixture containing at a minimum a silicon-, aluminum-, and/orphosphorous-composition, and a templating agent, should be in the rangeof from 2 to 10.

[0039] In one preferred embodiment, when a templating agent is used inthe synthesis of a molecular sieve, it is preferred that the templatingagent is substantially, preferably completely, removed aftercrystallization by numerous well known techniques, for example, heattreatments such as calcination. Calcination involves contacting themolecular sieve containing the templating agent with a gas, preferablycontaining oxygen, at any desired concentration at an elevatedtemperature sufficient to either partially or completely decompose andoxidize the templating agent.

[0040] Treatment With Metal Hydride Compounds.

[0041] According to the present invention, the cage volume of amicroporous molecular sieve is modified by a method comprising the stepsof a) introducing a metal hydride compound within the cages of saidmicroporous molecular sieve and b) reacting said metal hydride compoundwith the acid groups located in the cages of the molecular sieve. Themetal hydride compound is selected from the group consisting of hydridesof metals of Groups 1 and 2 of the Periodic Table, compounds of formulaM¹M²H₄ and mixtures thereof, M¹ being a metal belonging to Group 13 ofthe Periodic Table and M² being a metal belonging to Group 1 of thePeriodic Table [using the IUPAC numbering system described in the CRCHandbook of Chemistry and Physics, 78th Edition, CRC Press, Boca Raton,Fla. (1997)].

[0042] This treatment can be applied to various types of molecularsieves, including small pore, medium pore and large pore molecularsieves. An important feature of the present invention is that the metalhydride compound (hereinafter referred to as Treating Agent) must beable to penetrate within the cages of the molecular sieve. Before usingthe Treating Agent, it is thus preferred to submit the molecular sieveto a heat treatment or calcination in order to remove the compounds thatmay be present in the void volume of the molecular sieve. Typicalcalcination temperatures are in the range from about 400° C. to about1,000° C., preferably from about 500° C. to about 800° C., and mostpreferably from about 550° C. to about 700° C. Calcination preferablytakes place in an environment such as air, nitrogen, helium, flue gas(combustion product lean in oxygen), or any combination thereof.

[0043] Also, it is preferable to use a Treating Agent having a kineticdiameter no larger (equal to or smaller), preferably smaller than thepore opening size of the molecular sieve. In a preferred embodiment, theTreating Agent is incorporated within the cages of ametalloaluminophosphate molecular sieve, most preferably a small poremetalloaluminophosphate molecular sieve.

[0044] The metal hydride compound is preferably selected from the groupconsisting of LiH, NaH, KH, CaH₂, LiAlH₄, NaAlH₄, KAlH₄, LiBH₄, NaBH₄,KBH₄, and mixtures thereof, more preferably selected from the groupconsisting of LiAlH₄, NaBH₄.

[0045] The Treating Agent can be introduced within the void volume ofthe molecular sieve by various methods that involve contacting themolecular sieve with the Treating Agent. One method consists in placingthe molecular sieve in a gas atmosphere containing the Treating Agent,optionally in the presence of a diluting inert gas. Another methodconsists in contacting a liquid Treating Agent or a solution or a slurryof the Treating Agent with the microporous molecular sieve underconditions allowing the Treating Agent to reach the channels and cageswithin the framework of the molecular sieve. Non-limiting examples ofsuch conditions include incipient wetness, immersion in the liquid withor without stirring. The solvent is preferably an organic aproticsolvent such as, for example, acetonitrile, dimethyl ether, diethylether, tetrahydrofuran, dimethyl formamide, liquid hydrocarbons such asbenzene, toluene, alkanes having from 5 to 20 carbon atoms, cycloalkaneshaving from 5 to 20 carbon atoms, and mixtures thereof. In a preferredembodiment, contacting the molecular sieve with the Treating Agent takesplace under conditions that avoid the presence of protic substances,such as for example, water and/or alcohols. For this purpose, theequipment, molecular sieves and solvents are carefully cleaned, driedand purified before contacting the molecular sieve with the TreatingAgent.

[0046] The treatment may be carried out within a wide range oftemperatures, including temperatures below room temperature, at roomtemperature and temperatures above room temperature, depending on thephysical and chemical properties of the molecular sieve and TreatingAgent used. A convenient range of temperature is from room temperatureup to 500° C., provided the Treating Agent is stable at the chosentemperature. For temperature sensitive Treating Agents, typicalpreferred temperatures range from room temperature to 150° C., morepreferably from room temperature to 100° C.

[0047] Without being bound to any particular theory, the Treating Agentis believed to react within the void volume of the molecular sieve withthe molecular sieve acid groups (OH groups) located in the cages of themolecular sieve. The reaction is accompanied by hydrogen release andresults in binding of metal compounds to the molecular sieve framework,resulting in a first treated molecular sieve. The first treatedmolecular sieve thus has acid sites within its intracrystalline cagesbound with a metal compound, the metal compound being selected from thegroup consisting of hydrides of metals of Groups 1 and 2 of the PeriodicTable, compounds of formula M¹M²H₄ and mixtures thereof, M¹ being ametal belonging to Group 13 of the Periodic Table and M² being a metalbelonging to Group 1 of the Periodic Table. Preferably, M¹ is aluminum,boron, or a mixture of aluminum and boron. The first treated molecularsieve is then typically submitted to a thermal treatment, in order toremove residual treating material, and to restore at least a portion,preferably essentially all, of the molecular sieve OH groups present inthe channels and cages of the molecular sieve. Optionally, this thermaltreatment is performed in the presence of a chemical agent which helpsrestore the molecular sieve OH groups. Non-limiting examples of suchagents include water, alcohols, such as methanol or ethanol, nitrousoxides, carbon monoxide, carbon dioxide, sources of ammonia, andmixtures thereof. In a preferred embodiment, the agent that helpsrestore the molecular sieve OH groups is water or methanol, morepreferably, water, most preferably water in the vapor phase. Thermaltreatment of the first treated molecular sieve is typically carried outat a temperature of from about 100° C. to about 700° C., preferably from30° C. to 400° C., most preferably from 50° C. to 200° C. The durationof the thermal treatment can vary within wide limits, depending on theTreating Agent used or depending on whether a chemical agent is used tohelp restore the molecular sieve OH groups. Typical durations range from10 minutes to 48 hours, preferably from 20 minutes to 24 hours, morepreferably from 30 minutes to 16 hours.

[0048] In the embodiment in which thermal treatment is carried out inthe presence of agent that helps restore the molecular sieve OH groups,the agent is preferably in the gas phase and thermal treatment iscarried out at a temperature of from room temperature to 500° C.,preferably of from 25° C. to 300° C., more preferably of from 50° C. to200° C.

[0049] Thermal treatment may optionally be followed by a calcinationstep. Typical calcination temperatures are in the range from about 400°C. to about 1,000° C., preferably from about 500° C. to about 800° C.,and most preferably from about 550° C. to about 700° C., preferably in acalcination environment such as air, steam, nitrogen, helium, flue gas(combustion product lean in oxygen), or any combination thereof. In anembodiment, thermal treatment and calcination can be carried outsimultaneously, optionally in the presence of the agent that helpsrestore the molecular sieve OH groups.

[0050] After thermal treatment, optionally accompanied or followed bycalcination, a second treated molecular sieve is obtained. This secondtreated molecular sieve has a compound containing at least one M-Ogroup, preferably containing only M-O groups, and hereinafter referredto as “Volume Modifier”, within its cages and/or channels. Preferably,the Volume Modifier is present in an amount sufficient to fill as muchas possible of the void volume (channels and cages, preferably thecages) of the molecular sieve, without affecting the catalytic activityof the molecular sieve. The preferred weight and volume of VolumeModifier will vary within a wide range of possible limits, depending onthe molecular sieve used, in particular its channel and cage volumesize, the size and chemical nature of the Treating Agent and the desiredcatalytic performances. For example, in the case of SAPO-56, void volumereductions of up to about 50% lead to significant catalyticimprovements.

[0051] In order to achieve the desired level of void volume reduction,the treatment sequence described above can be repeated as many times asnecessary. Each treatment sequence will result in the formation ofadditional Volume Modifier within the void volume of the molecular sieve

[0052] Typically, molecular sieves used in catalytic processes,especially on a commercial scale, are formulated into catalystcompositions. Formulation can occur at several stages of the molecularsieve treatment according to the present invention: before treatment,after formation of the first treated molecular sieve but beforeformation of the second treated molecular sieve (i.e. before the thermaltreatment step) or after formation of the second treated molecular sieve(i.e. after the thermal treatment step). Catalyst formulation can thusbe done either on the crystalline molecular sieve, on the first treatedmolecular sieve or on the second treated molecular sieve, hereincollectively referred to as molecular sieve composition.

[0053] In all three embodiments, a catalyst composition is made orformulated by combining a molecular sieve composition, with a binderand/or a matrix material. These formulated catalyst compositions arethen, formed into useful shape and sized particles by well-knowntechniques such as spray drying, pelletizing, extrusion, and the like.

[0054] There are many different binders that are useful in formingcatalyst compositions according to the invention. Non-limiting examplesof binders that are useful alone or in combination include various typesof hydrated alumina, silicas, and/or other inorganic oxide sol. Onepreferred alumina containing sol is aluminum chlorhydrol. The inorganicoxide sol acts like glue binding the synthesized molecular sieves andother materials such as the matrix together, particularly after thermaltreatment. Upon heating, the inorganic oxide sol, preferably having alow viscosity, is converted into an inorganic oxide matrix component.For example, an alumina sol will convert to an aluminum oxide matrixfollowing heat treatment.

[0055] In a preferred embodiment, the molecular sieve composition iscombined with one or more matrix material(s). Matrix materials aretypically effective in reducing overall catalyst cost, act as thermalsinks assisting in shielding heat from the catalyst composition forexample during regeneration, densifying the catalyst composition, andincreasing catalyst strength such as crush strength and attritionresistance.

[0056] Non-limiting examples of matrix materials include one or more of:clays, rare earth metal oxides, non-active metal oxides includingmagnesia, thoria, beryllia, quartz, silica or sols, and mixturesthereof, for example silica-magnesia, silica-zirconia, silica-titania,silica-alumina and silica-alumina-thoria. Preferably, the matrixmaterial is a clay.

[0057] Upon combining the molecular sieve composition and the matrixmaterial, and/or binder, in a liquid to form a slurry, mixing,preferably rigorous mixing is needed to produce a substantiallyhomogeneous mixture containing the molecular sieve composition.Non-limiting examples of suitable liquids include one or a combinationof water, alcohol, ketones, aldehydes, and/or esters. The most preferredliquid is water.

[0058] In one embodiment, the slurry of the molecular sieve composition,binder and matrix material is mixed or milled to achieve a sufficientlyuniform slurry of sub-particles of the molecular sieve catalystcomposition that is then fed to a forming unit that produces themolecular sieve catalyst composition. In a preferred embodiment, theforming unit is a spray dryer. Typically, the forming unit is maintainedat a temperature sufficient to remove most of the liquid from theslurry, and from the resulting molecular sieve catalyst composition. Theresulting catalyst composition when formed in this way takes the form ofmicro spheres.

[0059] When a spray drier is used as the forming unit, typically, theslurry of the molecular sieve composition and matrix material, andoptionally a binder, is co-fed to the spray drying volume with a dryinggas with an average inlet temperature ranging from 200° C. to 550° C.,and a combined outlet temperature ranging from 100° C. to about 225° C.In an embodiment, the average diameter of the spray dried formedcatalyst composition is from about 40 μm to about 300 μm, preferablyfrom about 50 μm to about 250 μm, more preferably from about 50 μm toabout 200 μm, and most preferably from about 65 μm to about 90 μm.

[0060] Once the catalyst composition is formed in a substantially dry ordried state, to further harden and/or activate the formed catalystcomposition, a heat treatment such as calcination, at an elevatedtemperature is usually performed. In the embodiment where formulation ofthe first treated molecular sieve is performed, this calcinationtreatment can replace or be part of the thermal treatment used togenerate the compound having at least one M-O bond in the cages and/orchannels of the molecular sieve. A conventional calcination environmentto harden the catalyst particles is air that typically includes a smallamount of water vapor. Typical calcination temperatures are in the rangefrom about 400° C. to about 1,000° C., preferably from about 500° C. toabout 800° C., and most preferably from about 550° C. to about 700° C.,preferably in a calcination environment such as air, nitrogen, helium,flue gas (combustion product lean in oxygen), or any combinationthereof.

[0061] In a preferred embodiment, the catalyst composition is heated innitrogen at a temperature of from about 600° C. to about 700° C. Heatingis carried out for a period of time typically from 30 minutes to 15hours, preferably from 1 hour to about 10 hours, more preferably fromabout 1 hour to about 5 hours, and most preferably from about 2 hours toabout 4 hours.

[0062] Catalytic Processes

[0063] The molecular sieve compositions and catalyst compositionsdescribed above are useful in a variety of processes including:cracking, of for example a naphtha feed to light olefin(s) or highermolecular weight (MW) hydrocarbons to lower MW hydrocarbons;hydrocracking, of for example heavy petroleum and/or cyclic feedstock;isomerization, of for example aromatics such as xylene, polymerization,of for example one or more olefin(s) to produce a polymer product;reforming; hydrogenation; dehydrogenation; dewaxing, of for examplehydrocarbons to remove straight chain paraffins; absorption, of forexample alkyl aromatic compounds for separating out isomers thereof;alkylation, of for example aromatic hydrocarbons such as benzene andalkyl benzene, optionally with propylene to produce cumeme or with longchain olefins; transalkylation, of for example a combination of aromaticand polyalkylaromatic hydrocarbons; dealkylation; hydrodecylization;disproportionation, of for example toluene to make benzene andparaxylene; oligomerization, of for example straight and branched chainolefin(s); and dehydrocyclization.

[0064] The preferred process of the invention is a process directed tothe conversion of a feedstock comprising one or more oxygenates to oneor more olefin(s).

[0065] In a preferred embodiment of the process of the invention, thefeedstock contains one or more oxygenates, more specifically, one ormore organic compound(s) containing at least one oxygen atom. In a morepreferred embodiment, the feedstock contains methanol and/or dimethylether, and most preferably methanol.

[0066] The feedstock containing one or more oxygenates, is converted inthe presence of a molecular sieve catalyst composition into olefin(s)having 2 to 6 carbons atoms, most preferably ethylene and/or propylene.

[0067] In one embodiment, the feedstock can contain one or morediluent(s), typically used to reduce the concentration of the feedstock,and generally non-reactive to the feedstock or molecular sieve catalystcomposition. Non-limiting examples of diluents include helium, argon,nitrogen, carbon monoxide, carbon dioxide, water, essentiallynon-reactive paraffins (especially alkanes such as methane, ethane, andpropane), essentially non-reactive aromatic compounds, and mixturesthereof. The most preferred diluents are water and nitrogen, with waterbeing particularly preferred. The diluent is used either in a liquid ora vapor form, or a combination thereof. The diluent is either addeddirectly to a feedstock entering into a reactor or added directly into areactor, or added with a molecular sieve catalyst composition.

[0068] The process for converting one or more oxygenates to olefins, inthe presence of a molecular sieve catalyst composition of the invention,is carried out in a reactor system, operated as a fixed bed process, afluidized bed process (including a turbulent bed process), preferably acontinuous fluidized bed process, and most preferably a continuous highvelocity fluidized bed process. The processes of the invention can takeplace in a variety of catalytic reactors such as hybrid reactors thathave a dense bed or fixed bed reaction zones and/or fast fluidized bedreaction zones coupled together, circulating fluidized bed reactors,riser reactors, and the like. Suitable reactor types are described infor example U.S. Pat. No. 4,076,796, U.S. Pat. No. 6,287,522 (dualriser), and Fluidization Engineering, D. Kunii and O. Levenspiel, RobertE. Krieger Publishing Company, New York, N.Y. 1977, which are all hereinfully incorporated by reference. The preferred reactor type are riserreactors generally described in Riser Reactor, Fluidization andFluid-Particle Systems, pages 48 to 59, F. A. Zenz and D. F. Othmo,Reinhold Publishing Corporation, New York, 1960, and U.S. Pat. No.6,166,282 (fast-fluidized bed reactor), and U.S. patent application Ser.No. 09/564,613 filed May 4, 2000 (multiple riser reactor), which are allherein fully incorporated by reference.

[0069] In the preferred embodiment, a fluidized bed process or highvelocity fluidized bed process includes a reactor system, a regenerationsystem and a recovery system.

[0070] The reactor system preferably is a fluid bed reactor systemhaving a first reaction zone within one or more riser reactor(s) and asecond reaction zone within at least one disengaging vessel, preferablycomprising one or more cyclones. In one embodiment, the one or moreriser reactor(s) and disengaging vessel is contained within a singlereactor vessel. Fresh feedstock, preferably containing one or moreoxygenates, optionally with one or more diluent(s), is fed to the one ormore riser reactor(s) in which a molecular sieve catalyst composition orcoked version thereof is introduced. In one embodiment, the molecularsieve catalyst composition or coked version thereof is contacted with aliquid or gas, or combination thereof, prior to being introduced to theriser reactor(s), preferably the liquid is water or methanol, and thegas is an inert gas such as nitrogen.

[0071] In an embodiment, the amount of fresh feedstock fed separately orjointly with a vapor feedstock, to a reactor system is in the range offrom 0.1 weight percent to about 85 weight percent, preferably fromabout 1 weight percent to about 75 weight percent, more preferably fromabout 5 weight percent to about 65 weight percent based on the totalweight of the feedstock including any diluent contained therein. Theliquid and vapor feedstocks are preferably the same composition, orcontain varying proportions of the same or different feedstock with thesame or different diluent.

[0072] The feedstock entering the reactor system is preferablyconverted, partially or fully, in the first reactor zone into a gaseouseffluent that enters the disengaging vessel along with a coked molecularsieve catalyst composition. In the preferred embodiment, cyclone(s)within the disengaging vessel are designed to separate the molecularsieve catalyst composition, preferably a coked molecular sieve catalystcomposition, from the gaseous effluent containing one or more olefin(s)within the disengaging zone. Cyclones are preferred, however, gravityeffects within the disengaging vessel will also separate the catalystcompositions from the gaseous effluent. Other methods for separating thecatalyst compositions from the gaseous effluent include the use ofplates, caps, elbows, and the like.

[0073] In one embodiment of the disengaging system, the disengagingsystem includes a disengaging vessel, typically a lower portion of thedisengaging vessel is a stripping zone. In the stripping zone the cokedmolecular sieve catalyst composition is contacted with a gas, preferablyone or a combination of steam, methane, carbon dioxide, carbon monoxide,hydrogen, or an inert gas such as argon, preferably steam, to recoveradsorbed hydrocarbons from the coked molecular sieve catalystcomposition that is then introduced to the regeneration system.

[0074] The conversion temperature employed in the conversion process,specifically within the reactor system, is in the range of from about200° C. to about 1000° C., preferably from about 250° C. to about 800°C., more preferably from about 250° C. to about 750° C., yet morepreferably from about 300° C. to about 650° C., yet even more preferablyfrom about 350° C. to about 600° C. most preferably from about 350° C.to about 550° C.

[0075] The conversion pressure employed in the conversion process,specifically within the reactor system, varies over a wide rangeincluding autogenous pressure. The conversion pressure is based on thepartial pressure of the feedstock exclusive of any diluent therein.Typically the conversion pressure employed in the process is in therange of from about 0.1 kPaa to about 5 MPaa, preferably from about 5kPaa to about 1 MPaa, and most preferably from about 20 kpaa to about500 kPaa.

[0076] The weight hourly space velocity (WHSV), particularly in aprocess for converting a feedstock containing one or more oxygenates inthe presence of a molecular sieve catalyst composition within a reactionzone, is defined as the total weight of the feedstock excluding anydiluents to the reaction zone per hour per weight of molecular sieve inthe molecular sieve catalyst composition in the reaction zone. The WHSVis maintained at a level sufficient to keep the catalyst composition ina fluidized state within a reactor. Typically, the WHSV ranges fromabout 1 hr⁻¹ to about 5000 hr⁻¹, preferably from about 2 hr⁻¹ to about3000 hr⁻¹, more preferably from about 5 hr⁻¹ to about 1500 hr⁻¹, andmost preferably from about 10 hr⁻¹ to about 1000 hr⁻¹. In one preferredembodiment, the WHSV is greater than 20 hr⁻¹, preferably the WHSV forconversion of a feedstock containing methanol and dimethyl ether is inthe range of from about 20 hr⁻¹ to about 300 hr⁻¹.

[0077] The superficial gas velocity (SGV) of the feedstock includingdiluent and reaction products within the reactor system is preferablysufficient to fluidize the molecular sieve catalyst composition within areaction zone in the reactor. The SGV in the process, particularlywithin the reactor system, more particularly within the riserreactor(s), is at least 0.1 meter per second (m/sec), preferably greaterthan 0.5 m/sec, more preferably greater than 1 m/sec, even morepreferably greater than 2 m/sec, yet even more preferably greater than 3m/sec, and most preferably greater than 4 m/sec.

[0078] The coked (used) molecular sieve catalyst composition iswithdrawn from the disengaging vessel and introduced to the regenerationsystem. The regeneration system comprises a regenerator where the cokedcatalyst composition is contacted with a regeneration medium, preferablya gas containing oxygen, under general regeneration conditions oftemperature, pressure and residence time. The regeneration temperatureis in the range of from about 200° C. to about 1500° C., preferably fromabout 300° C. to about 1000° C., more preferably from about 450° C. toabout 750° C., and most preferably from about 550° C. to 700° C. Theregeneration pressure is in the range of from about 15 psia (103 kPaa)to about 500 psia (3448 kPaa), preferably from about 20 psia (138 kPaa)to about 250 psia (1724 kPaa), more preferably from about 25 psia (172kPaa) to about 150 psia (1034 kPaa), and most preferably from about 30psia (207 kPaa) to about 60 psia (414 kPaa).

[0079] In an embodiment, a portion of the molecular sieve catalystcomposition from the regenerator is returned directly to the one or moreriser reactor(s), or indirectly, by pre-contacting with the feedstock,or contacting with fresh molecular sieve catalyst composition, orcontacting with a regenerated molecular sieve catalyst composition or acooled regenerated molecular sieve catalyst composition described below.

[0080] The burning of coke is an exothermic reaction, and in anembodiment, the temperature within the regeneration system is controlledby various techniques in the art including feeding a cooled gas to theregenerator vessel, operated either in a batch, continuous, orsemi-continuous mode, or a combination thereof. A preferred techniqueinvolves withdrawing the regenerated molecular sieve catalystcomposition from the regeneration system and passing the regeneratedmolecular sieve catalyst composition through a catalyst cooler thatforms a cooled regenerated molecular sieve catalyst composition. Thecatalyst cooler, in an embodiment, is a heat exchanger that is locatedeither internal or external to the regeneration system. Other methodsfor operating a regeneration system are in disclosed U.S. Pat. No.6,290,916 (controlling moisture), which is herein fully incorporated byreference.

[0081] The regenerated molecular sieve catalyst composition withdrawnfrom the regeneration system, preferably from the catalyst cooler, iscombined with a fresh molecular sieve catalyst composition and/orre-circulated molecular sieve catalyst composition and/or feedstockand/or fresh gas or liquids, and returned to the riser reactor(s). Inanother embodiment, the regenerated molecular sieve catalyst compositionwithdrawn from the regeneration system is returned to the riserreactor(s) directly, preferably after passing through a catalyst cooler.In one embodiment, a carrier, such as an inert gas, feedstock vapor,steam or the like, semi-continuously or continuously, facilitates theintroduction of the regenerated molecular sieve catalyst composition tothe reactor system, preferably to the one or more riser reactor(s).

[0082] By controlling the flow of the regenerated molecular sievecatalyst composition or cooled regenerated molecular sieve catalystcomposition from the regeneration system to the reactor system, theoptimum level of coke on the molecular sieve catalyst compositionentering the reactor is maintained. There are many techniques forcontrolling the flow of a molecular sieve catalyst composition describedin Michael Louge, Experimental Techniques, Circulating Fluidized Beds,Grace, Avidan and Knowlton, eds., Blackie, 1997 (336-337), which isherein incorporated by reference.

[0083] Coke levels on the molecular sieve catalyst composition aremeasured by withdrawing from the conversion process the molecular sievecatalyst composition at a point in the process and determining itscarbon content. Typical levels of coke on the molecular sieve catalystcomposition, after regeneration is in the range of from 0.01 weightpercent to about 15 weight percent, preferably from about 0.1 weightpercent to about 10 weight percent, more preferably from about 0.2weight percent to about 5 weight percent, and most preferably from about0.3 weight percent to about 2 weight percent based on the total weightof the molecular sieve and not the total weight of the molecular sievecatalyst composition.

[0084] The gaseous effluent is withdrawn from the disengaging system andis passed through a recovery system. There are many well known recoverysystems, techniques and sequences that are useful in separatingolefin(s) and purifying olefin(s) from the gaseous effluent. Recoverysystems generally comprise one or more or a combination of a variousseparation, fractionation and/or distillation towers, columns,splitters, or trains, reaction systems such as ethylbenzene manufacture(U.S. Pat. No. 5,476,978) and other derivative processes such asaldehydes, ketones and ester manufacture (U.S. Pat. No. 5,675,041), andother associated equipment for example various condensers, heatexchangers, refrigeration systems or chill trains, compressors,knock-out drums or pots, pumps, and the like.

[0085] Non-limiting examples of these towers, columns, splitters ortrains used alone or in combination include one or more of ade-methanizer, preferably a high temperature de-methanizer, ade-ethanizer, a de-propanizer, a wash tower often referred to as acaustic wash tower and/or quench tower, absorbers, adsorbers, membranes,ethylene (C2) splitter, propylene (C3) splitter, butene (C4) splitter,and the like.

[0086] Various recovery systems useful for recovering predominatelyolefin(s), preferably prime or light olefin(s) such as ethylene,propylene and/or butene are described in U.S. Pat. No. 5,960,643(secondary rich ethylene stream), U.S. Pat. Nos. 5,019,143, 5,452,581and 5,082,481 (membrane separations), U.S. Pat. No. 5,672,197 (pressuredependent adsorbents), U.S. Pat. No. 6,069,288 (hydrogen removal), U.S.Pat. No. 5,904,880 (recovered methanol to hydrogen and carbon dioxide inone step), U.S. Pat. No. 5,927,063 (recovered methanol to gas turbinepower plant), and U.S. Pat. No. 6,121,504 (direct product quench), U.S.Pat. No. 6,121,503 (high purity olefins without superfractionation), andU.S. Pat. No. 6,293,998 (pressure swing adsorption), which are allherein fully incorporated by reference.

[0087] Generally accompanying most recovery systems is the production,generation or accumulation of additional products, by-products and/orcontaminants along with the preferred prime products. The preferredprime products, the light olefins, such as ethylene and propylene, aretypically purified for use in derivative manufacturing processes such aspolymerization processes. Therefore, in the most preferred embodiment ofthe recovery system, the recovery system also includes a purificationsystem. For example, the light olefin(s) produced particularly in amethanol-to-olefins process are passed through a purification systemthat removes low levels of by-products or contaminants.

[0088] Non-limiting examples of contaminants and by-products includegenerally polar compounds such as water, alcohols, carboxylic acids,ethers, carbon oxides, sulfur compounds such as hydrogen sulfide,carbonyl sulfides and mercaptans, ammonia and other nitrogen compounds,arsine, phosphine and chlorides. Other contaminants or by-productsinclude hydrogen and hydrocarbons such as acetylene, methyl acetylene,propadiene, butadiene and butyne.

[0089] Other recovery systems that include purification systems, forexample for the purification of olefin(s), are described in Kirk-OthmerEncyclopedia of Chemical Technology, 4th Edition, Volume 9, John Wiley &Sons, 1996, pages 249-271 and 894-899, which is herein incorporated byreference. Purification systems are also described in for example, U.S.Pat. No. 6,271,428 (purification of a diolefin hydrocarbon stream), U.S.Pat. No. 6,293,999 (separating propylene from propane), and U.S. patentapplication Ser. No. 09/689,363 filed Oct. 20, 2000 (purge stream usinghydrating catalyst), which is herein incorporated by reference.

[0090] Typically, in converting one or more oxygenates to olefin(s)having 2 or 3 carbon atoms, an amount of hydrocarbons, particularlyolefin(s), especially olefin(s) having 4 or more carbon atoms, and otherby-products are formed or produced. Included in the recovery systems ofthe invention are reaction systems for converting the products containedwithin the effluent gas withdrawn from the reactor or converting thoseproducts produced as a result of the recovery system utilized.

[0091] In an embodiment, an integrated process is directed to producinglight olefin(s) from a hydrocarbon feedstock, preferably a hydrocarbongas feedstock, more preferably methane and/or ethane. The first step inthe process is passing the gaseous feedstock, preferably in combinationwith a water stream, to a syngas production zone to produce a synthesisgas (syngas) stream. Syngas production is well known, and typical syngastemperatures are in the range of from about 700° C. to about 1200° C.and syngas pressures are in the range of from about 2 MPa to about 100MPa. Synthesis gas streams are produced from natural gas, petroleumliquids, and carbonaceous materials such as coal, recycled plastic,municipal waste or any other organic material, preferably synthesis gasstream is produced via steam reforming of natural gas.

[0092] Generally, a heterogeneous catalyst, typically a copper basedcatalyst, is contacted with a synthesis gas stream, typically carbondioxide and carbon monoxide and hydrogen to produce an alcohol,preferably methanol, often in combination with water. In one embodiment,the synthesis gas stream at a synthesis temperature in the range of fromabout 150° C. to about 450° C. and at a synthesis pressure in the rangeof from about 5 MPa to about 10 MPa is passed through a carbon oxideconversion zone to produce an oxygenate containing stream.

[0093] This oxygenate containing stream, or crude methanol, typicallycontains the alcohol product and various other components such asethers, particularly dimethyl ether, ketones, aldehydes, dissolved gasessuch as hydrogen methane, carbon oxide and nitrogen, and fuel oil. Theoxygenate containing stream, crude methanol, in the preferred embodimentis passed through a well known purification processes, distillation,separation and fractionation, resulting in a purified oxygenatecontaining stream, for example, commercial Grade A and AA methanol.

[0094] The oxygenate containing stream or purified oxygenate containingstream, optionally with one or more diluents, is contacted with one ormore molecular sieve catalyst composition described above in any one ofthe processes described above to produce a variety of prime products,particularly light olefin(s), ethylene and/or propylene. Non-limitingexamples of this integrated process are described in EP-B-0 933 345,which is herein fully incorporated by reference.

[0095] In another more fully integrated process, optionally with theintegrated processes described above, olefin(s) produced are directedto, in one embodiment, one or more polymerization processes forproducing various polyolefins. (See for example U.S. patent applicationSer. No. 09/615,376 filed Jul. 13, 2000, which is herein fullyincorporated by reference.)

[0096] Polymerization processes include solution, gas phase, slurryphase and a high pressure processes, or a combination thereof.Particularly preferred is a gas phase or a slurry phase polymerizationof one or more olefin(s) at least one of which is ethylene or propylene.

[0097] These polymerization processes utilize a polymerization catalystthat can include any one or a combination of the molecular sievecatalysts discussed above, however, the preferred polymerizationcatalysts are those Ziegler-Natta, Phillips-type, metallocene,metallocene-type and advanced polymerization catalysts, and mixturesthereof.

[0098] In preferred embodiment, the integrated process comprises apolymerizing process of one or more olefin(s) in the presence of apolymerization catalyst system in a polymerization reactor to produceone or more polymer products, wherein the one or more olefin(s) havingbeen made by converting an alcohol, particularly methanol, using amolecular sieve catalyst composition. The preferred polymerizationprocess is a gas phase polymerization process and at least one of theolefins(s) is either ethylene or propylene, and preferably thepolymerization catalyst system is a supported metallocene catalystsystem. In this embodiment, the supported metallocene catalyst systemcomprises a support, a metallocene or metallocene-type compound and anactivator, preferably the activator is a non-coordinating anion oralumoxane, or combination thereof, and most preferably the activator isalumoxane.

[0099] The polymers produced by the polymerization processes describedabove include linear low density polyethylene, elastomers, plastomers,high density polyethylene, low density polyethylene, polypropylene andpolypropylene copolymers. The propylene based polymers produced by thepolymerization processes include atactic polypropylene, isotacticpolypropylene, syndiotactic polypropylene, and propylene random, blockor impact copolymers.

EXAMPLES

[0100] In order to provide a better understanding of the presentinvention including representative advantages thereof, the followingexamples are offered. In these examples, X-ray Diffractograms wererecorded on a Philips PW 1840 powder diffractometer, using Ni-filteredCu Kα radiation (X=0.154 nm).

Example 1

[0101] Microcrystalline Molecular Sieve.

[0102] SAPO-34 was prepared according to the following procedure. Thefollowing ingredients were mixed, in sequence, into a uniform gel:pseudoboehmite alumina (Condea Pural SB-F) and H₂O, a solution of 85 wt% semi-conductor grade phosphoric acid and H₂O, colloidal silica (40%,Nalco), tetraethylammoniumhydroxide (35%, Sachem) and dipropylamine. Themolar ratio of the ingredients was:

[0103] 0.2 SiO₂: Al₂O₃:P₂O₅:0.88 TEAOH:1.56 DPA:50 H₂O

[0104] The synthesis mixture was placed in an stainless steel autoclave,stirred and heated to 170° C. for 35 hrs. The solid product was washedwith deionized water and dried. The solid product yield was 11%. XRDpattern shows that the product is SAPO-34.

Example 2

[0105] Treatment of SAPO-34 with LiAlH₄ or NaBH₄.

[0106] As synthesized SAPO-34 was calcined at 650° C. for 10 hours. Anamount of 3.0 g of calcined SAPO-34 was placed in a 100-ml round bottomflask. The flask was evacuated under vacuum and 30 ml of anhydroustetrahydrofuran (THF, Aldrich) was cannulated into the flask. Themixture was allowed to stir for 30 minutes and 2.0 mL of a 1.0 Msolution of lithium aluminium hydride in THF (available from Aldrich)was then slowly added via a gas-tight syringe. Gas evolution wasobserved upon addition of the hydride solution. The atomic ratio ofaluminum added to silicon in the molecular sieve was 0.5. The mixturewas stirred for 18 hours, separated by centrifuge and washed with 30 mLof THF. The solid obtained was then stirred in 30 mL of methanol for 12hours, separated and dried in an oven at 105° C. for 12 hours.

[0107] b) The procedure described in a) above was repeated, except 4.0mL of the 1.0 M lithium aluminium hydride solution was used.

[0108] c) SAPO-34 was calcined at 650° C. for 10 hours. An amount of 3.0g of calcined SAPO-34 was placed in a 100-ml round bottom flask. Theflask was evacuated under vacuum and 40 ml of anhydrousdimethylformamide (DMF, Aldrich) was cannulated into the flask. Themixture was allowed to stir for 30 minutes. Separately, an amount of 78mg of sodium borohydride (Aldrich) was dissolved in 5.0 mL of anhydrousDMF under nitrogen and the solution was added slowly via a gas-tightsyringe to the flask containing SAPO-34. Gas evolution was observed uponaddition of the hydride solution. The atomic ratio of boron added tosilicon in the molecular sieve was 0.5. The mixture was stirred for 24hours, separated by centrifuge and washed twice with 30 mL of methanol.The solid obtained was dried in an oven at 105° C. for 12 hours.

[0109] d) The procedure described in c) above was repeated, except 155mg of sodium borohydride dissolved in 5.0 mL of anhydrous DMF was used.

[0110] While the present invention has been described and illustrated byreference to particular embodiments, those of ordinary skill in the artwill appreciate that the invention lends itself to variations notnecessarily illustrated herein. For example, it is also contemplated themolecular sieves described herein are useful as absorbents, adsorbents,gas separators, detergents, water purifiers, and in other various usesin various areas such as agriculture and horticulture.

1. A method for modifying a microporous metalloaluminophosphatemolecular sieve, the method comprising the steps of a) introducing ametal hydride compound within the cages of said microporous molecularsieve and b) reacting said metal hydride compound with the acid groupslocated in the cages of the molecular sieve, wherein the metal hydridecompound is selected from the group consisting of hydrides of metals ofGroups 1 and 2 of the Periodic Table, compounds of formula M¹M²H₄ andmixtures thereof, M¹ being a metal belonging to Group 13 of the PeriodicTable and M² being a metal belonging to Group 1 of the Periodic Table.2. The method of claim 1, wherein M¹ is aluminum, boron, or a mixture ofaluminum and boron.
 3. The method of claim 1, wherein the metal hydridecompound is selected from the group consisting of LiH, NaH, KH, CaH₂,LiAlH₄, NaAlH₄, KAlH₄, LiBH₄, NaBH₄, KBH₄ and mixtures thereof.
 4. Themethod of claim 1, wherein reacting the metal hydride with the molecularsieve acid groups takes place at a temperature of from room temperatureto 150° C.
 5. The method of claim 1, wherein introducing the metalhydride compound within the cages of the microporous molecular sievetakes place by contacting the molecular sieve with a solution or aslurry of the metal hydride compound in an aprotic organic solvent. 6.The method of claim 5, wherein contacting the molecular sieve with asolution or a slurry of the metal hydride compound takes place underconditions that avoid the presence of water and/or alcohols.
 7. Themethod of claim 1, wherein the molecular sieve is a small pore or mediumpore metalloaluminophosphate molecular sieve.
 8. The method of claim 1,wherein the molecular sieve is SAPO-34 or SAPO-56.
 9. The method ofclaim 1, further comprising the step of c) restoring at least a portionof the acid groups located in the cages of the molecular sieve bysubmitting the molecular sieve to a thermal treatment.
 10. The method ofclaim 9, wherein thermal treatment takes place at a temperature of fromabout 30° C. to about 400° C.
 11. The method of claim 9, wherein thermaltreatment takes place at a temperature of from 50° C. to 150° C.
 12. Themethod of claim 9, wherein thermal treatment takes place in the presenceof water, an alcohol, such as methanol, ethanol or mixtures thereof,nitrous oxides, carbon monoxide, carbon dioxide, sources of ammonia, andmixtures thereof.
 13. The method of claim 9, wherein thermal treatmentis followed by a calcination step.
 14. A microcrystallinemetalloaluminophosphate molecular sieve having acid sites within itsintracrystalline cages bound with a metal compound, the metal compoundbeing selected from the group consisting of hydrides of metals of Groups1 and 2 of the Periodic Table, compounds of formula M¹M²H₄ and mixturesthereof, M¹ being a metal belonging to Group 13 of the Periodic Tableand M² being a metal belonging to Group 1 of the Periodic Table.
 15. Themicrocrystalline molecular sieve of claim 14, wherein the metal compoundis M¹M²H₄ and mixtures thereof M¹ being a metal belonging to Group 13 ofthe Periodic Table and M² being a metal belonging to Group 1 of thePeriodic Table.
 16. The molecular sieve of claim 15, wherein themolecular sieve has the AFX or CHA framework type.
 17. A method ofmaking molecular sieve catalyst particles, the method comprising a)combining a microcrystalline metalloaluminophosphate molecular sievehaving acid sites within its intracrystalline cages bound with a metalcompound, the metal compound being selected from the group consisting ofhydrides of metals of Groups 1 and 2 of the Periodic Table, compounds offormula M¹M²H₄ and mixtures thereof, M¹ being a metal belonging to Group13 of the Periodic Table and M² being a metal belonging to Group 1 ofthe Periodic Table, with at least one binder and optionally at least onematrix to form a catalyst preparation mixture; b) forming catalystparticles from the catalyst preparation mixture obtained at step a); c)submitting the catalyst particles to a thermal treatment at atemperature of from about 30° C. to about 700° C.
 18. The method ofclaim 17, wherein thermal treatment takes place in the presence ofwater, an alcohol, such as methanol, ethanol or mixtures thereof,nitrous oxides, carbon monoxide, carbon dioxide, sources of ammonia, andmixtures thereof.
 19. The method of claim 17, wherein the binder isalumina.
 20. The method of claim 17, wherein the matrix is a clay. 21.The method of claim 17, wherein forming catalyst particles from thecatalyst preparation mixture is performed by spray drying said catalystpreparation mixture.
 22. A process for making olefins from an oxygenatefeedstock comprising the steps of a) providing a metalloaluminophosphatemolecular sieve; b) introducing a metal hydride compound within thecages of said microporous molecular sieve; c) reacting said metalhydride compound with the acid groups located in the cages of themolecular sieve, wherein the metal hydride compound is selected from thegroup consisting of hydrides of metals of Groups 1 and 2 of the PeriodicTable, compounds of formula M¹M²H₄ and mixtures thereof, M¹ being ametal belonging to Group 13 of the Periodic Table and M² being a metalbelonging to Group 1 of the Periodic Table; d) restoring at least aportion of the acid groups located in the cages of the molecular sieveby submitting the molecular sieve to a thermal treatment; e) contactingthe molecular sieve obtained at step d) with the oxygenate feedstock; f)recovering an olefin product.